Downloaded from http://journals.lww.com/acsm-msse by BhDMf5ePHKbH4TTImqenVAHxkFJp/XpPk1L/H3vMGwqMxG9jwOd8eNorcHBXn3Nn83sAFg4Ze4Q= on 07/18/2018 Catecholamine Response to Exercise in Obese, Overweight, and Lean Adolescent Boys GEORGES JABBOUR 1,2 , SOPHIE LEMOINE-MOREL 1 , GRETCHEN A. CASAZZA 3 , YOUSSEF HALA 2 , ELIE MOUSSA 2 , and HASSANE ZOUHAL 1 1 Movement, Sport and Health Sciences Laboratory (M2S), UFR-APS, University of Rennes 2-ENS Cachan, Rennes, FRANCE; 2 Physiology of Motor Performance Laboratory, Physical Education Department, University of Balamand, Tripoli, LEBANON; and 3 Sports Performance Laboratory, University of California, Davis, Medical Center Sports Medicine Program, Sacramento, CA ABSTRACT JABBOUR, G., S. LEMOINE-MOREL, G. A. CASAZZA, Y. HALA, E. MOUSSA, and H. ZOUHAL. Catecholamine Response to Exercise in Obese, Overweight, and Lean Adolescent Boys. Med. Sci. Sports Exerc., Vol. 43, No. 3, pp. 408–415, 2011. Introduction: The aim of this study was to examine the effect of body fat percentage on the plasma catecholamine response to a cycling sprint test (CST) in sedentary adolescent boys. Methods: In this study, 31 adolescent boys (9 obese (% body fat = 31.0% T 3.0%), 11 overweight (% body fat = 24.0% T 1.6%), and 11 lean (% body fat = 16.0% T 1.9%)), matched for peak oxygen consumption, completed a CST consisting of six 6-s maximal sprints with 2 min of passive rest between each repetition. Performance of each subject was determined as the mean power output (PO mean ) developed during the CST. Plasma lactate, epinephrine, and norepinephrine concentrations were determined successively at rest, after a 10-min warm-up, immediately after the CST, and after 20 min of passive recovery. Results: Although groups were not different in age, height, or peak oxygen consumption (mLIkg j1 fat-free massImin j1 ), maximal epinephrine concentration was significantly (P G 0.05) higher in lean vs obese and was negatively correlated to body fat percentage (r = j0.60, P G 0.05). Maximal norepinephrine values were higher in lean versus overweight and obese, and a negative relationship was found between maximal norepinephrine concentration and body fat percentage (r = j0.60, P G 0.05). Maximal lactate concentration was higher in lean versus overweight and obese (14.7 T 3.3, 10.4 T 2.7, and 10.2 T 2.5 mM in lean, overweight, and obese, respectively). A signifi- cant relationship was also obtained between maximal norepinephrine and maximal epinephrine values with both maximal lactate concen- tration (r = 0.60 and r = 0.60, P G 0.05, respectively) and PO mean (r = 0.65 and r = 0.6, P G 0.05). Conclusions: Our results show that the catecholamine response to a CST was affected by body fat percentage, with reduced epinephrine and norepinephrine values in overweight and obese adolescents. Key Words: OBESITY, EPINEPHRINE, NOREPINEPHRINE, CYCLING, SPRINTING, LACTATE C hildhood obesity is a major, uncontrolled worldwide epidemic with serious psychosocial and medical consequences due to comorbidities such as early- onset dyslipidemia, hypertension, and insulin resistance (22). Childhood obesity is also considered a key predictor for obesity in adulthood (31). Obesity treatment programs rely on dietary changes combined with regular exercise for success- ful weight loss. The ability to mobilize adipose tissue fat for oxidization in muscle during exercise is important to the success of an exercise training–related weight loss program. Catecholamines are known to play a major role in the regu- lation of intermediary metabolism, affecting glucose pro- duction, muscle glycogen mobilization, and lipolysis (17), all of which affect exercise metabolism and performance (11). Reductions in the catecholamine response to exercise could disrupt fat mobilization and oxidation, preventing the desired loss of adipose in overweight or obese individuals. Human studies indicate that obese and overweight indi- viduals have altered hormone responses both at rest (5,32) and in response to stimuli such as hypoglycemia or exer- cise (5,20,30). Obese individuals have been shown to exhibit significantly reduced growth hormone and catecholamine responses during exercise (7,20,30). Whether the altered hormonal response is the result of or contributes to the cause of obesity is uncertain (3). The majority of the studies examining the effect of obesity on exercise-associated hor- monal responses have been conducted on adults. There is little information on the effects of obesity on the catechol- amine response at rest and during exercise in adolescents. Eliakim et al. (7) observed a blunted catecholamine response to exercise in obese compared with lean adolescents (girls and boys were combined). The exercise consisted of ten Address for correspondence: Hassane Zouhal, Ph.D., Movement, Sport and Sciences Laboratory (M2S), UFR-APS, University of Rennes, 2, Avenue Charles Tillon, CS 24414, 35044 Rennes Cedex, France; E-mail: hassane.zouhal@univ-rennes2.fr. Submitted for publication February 2010. Accepted for publication June 2010. 0195-9131/11/4303-0408/0 MEDICINE & SCIENCE IN SPORTS & EXERCISE Ò Copyright Ó 2011 by the American College of Sports Medicine DOI: 10.1249/MSS.0b013e3181f1bef3 408 BASIC SCIENCES Copyright © 2011 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.